It is generally agreed that diet plays a large role in controlling the risk of developing cancers and that increased consumption of fruits and vegetables may reduce cancer incidences in humans. The presence of certain minor chemical components in plants may provide a major protection mechanism when delivered to mammalian cells. Moreover, providing pharmaceuticals, nutritional supplements, or foods fortified or supplemented with cancer-fighting chemical components derived from plants may provide additional health benefits. An important trend in the U.S. food industry is to promote health conscious food products.
Cruciferous vegetables contain phytochemical precursors to potent chemoprotectants, especially glucoraphanin (which is also known as sulforaphane glucosinolate or 4-methylsulfinylbutyl glucosinolate) and its associated conversion product sulforaphane, that appear to trigger carcinogen detoxification mechanisms when delivered to mammalian cells. Glucosinolates are found in dicotyledenous plants and most commonly in the Brassicaceae (Cruciferae) families. Glucosinolates are sulfur-containing compounds of the general structure:
Glucosinolates include an R-group derived from amino acids and a thioglucosidic link to the carbon of a sulphonated oxime. The thioglucosidic bonds of the glucosinolates are hydrolyzed by beta-thioglucosidases into unstable glucosinolate aglycones, which undergo spontaneous rearrangement into chemoprotectant isothiocyanates, such as sulforaphane, and other compounds, such as nitriles and thiocyanates.
In addition to reducing the risk of certain cancers, glucoraphanin, through its bioactive conversion product sulforaphane, has recently been shown effective in destroying organisms responsible for causing the majority of stomach ulcers and may provide novel approaches for reducing the risk of developing cardiovascular and ocular diseases. Efforts are being undertaken to gain approval for making label claims on food products either naturally high in these agents or for foods containing added crucifer chemoprotectants. Products containing chemoprotectant additives, although without such label claims, are already on the market.
Cruciferous vegetables also contain other compounds, such as indole glucosinolates (for example, 4-hydroxyglucobrassican), which may be problematic for maintaining good health. Not only are these compounds weak inducers of the carcinogen detoxification system, but they can also induce systems which may bioactivate certain pro-carcinogens. Therefore, it is advantageous to produce glucoraphanin-containing preparations containing as little residual indole glucosinolates, or other adverse compounds, as possible.
The production of glucosinolates, particularly glucoraphanin, is problematic because of their high cost. Until the present invention, the best production source of glucoraphanin was expensive specialty broccoli cultivars. The considerable health potential of glucosinolates has not been realized due to the high cost of sourcing glucoraphanin. Hence, there is a need to provide alternative methods for producing high yields of glucosinolates, particularly glucoraphanin.
The present process, which is both technically straightforward and attractive from a production cost standpoint, provides such improvements. Indeed, the present process makes it possible to prepare extracts enriched with chemoprotectant precursor compounds, particularly glucoraphanin, from relatively inexpensive radish seeds while offering the health benefits of extracts prepared from substantially more expensive broccoli cultivars.